Cancer cytogenetics expertise is needed to provide critical data for research projects in many Programs of the Sidney Kimmel Comprehensive Cancer Center (SKCCC). The Cancer Cytogenetics Shared Resource has been providing such expertise to SKCCC researchers since 1986. A full array of analyses is offered; these include metaphase analysis using traditional G-banding and fluorescent in situ hybridization (FISH) technologies, ranging from single locus probes through multicolor FISH including Spectral Karyotyping (SKY). Consultations to determine the best cytogenetic technique to answer the investigator's question are an integral part of the service provided. Up-to-date techniques and highly experienced personnel have been the foundation of this facility and provide major value to the users. The Core also coordinates with services offered by the Tissue Microarray Core, such as tissue in-situ hybridization, and the Microarray Core, such as genomic copy-number and SNP-chip assays, to provide a seamless continuum of genomic analysis technologies in the SKCCC. Lay: The Cytogenetics Core Resource provides expert analysis of chromosomes, the structures that carry our DNA. Chromosome abnormalities in cancer are common, and researchers often need characterization of chromosome changes that are present in cancer cell lines.